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Hi, You should have the matrix for calculating transformations from native to MNI and viceversa. You should choose the transformation matrix for moving between spaces you want. Volume calculation should take only into account your region of interest. You have to make mask of this region on native space because of inter subject differences. See FSL wiki for detailed information about the significant of the numbers and the processing... Best, Rosalia. El 10/05/2013 07:45, "chenchunhuichina" <[log in to unmask]> escribió: > ** > Thanks Rosalia! > > But I am still confused. The IFG ROI was defined from aal templete, which > was in MNI space. How can I "make the mask of this region on native, > structural image"? Do you mean warp the ROI into native space? then why > should normalize back to MNI space? > Also, what does numbers mean in VBM a modulated images, the volume of a > voxel? So I only sum up the numbers of voxels within the ROI or do I need > to times it with 8 (2mm *2mm*2mm voxel size), or some other calculation? > > Thanks for the help! > > 2013-05-10 > ------------------------------ > Chunhui Chen > _________________ > > State Key Laboratory of Cognitive Neuroscience and Learning > Beijing Normal University > Beijing, China 100875 > ------------------------------ > *发件人：* Rosalia Dacosta Aguayo > *发送时间：* 2013-05-10 13:04:19 > *收件人：* FSL > *抄送：* > *主题：* Re: [FSL] How to calculate Region volume on VBM results? > > Hi Chenchui, > > It would be better to make the mask of this region on native, structural > image for every subject. Then, normalize the image and the mask into MNI > space and binarize and threshold the mask. Finally, you can calculate the > volume with fslmeants. > > I hope this helps, > Best > Rosalia. > El 10/05/2013 03:30, "chenchunhuichina" <[log in to unmask]> > escribió: > >> ** >> Hello FSLers, >> >> I was using FSL-VBM for structural data analysis and it runs smoothly at >> voxel level. However, I want to calcualte the volume of a region, say IFG, >> how can I do that? should I do it in native space or in normalized space? >> I am not quite sure what the numbers mean for each voxel, can I sum >> voxels up to get total volume of a region? >> >> Thanks for any help! >> >> 2013-05-09 >> ------------------------------ >> Chunhui Chen >> _________________ >> >> State Key Laboratory of Cognitive Neuroscience and Learning >> Beijing Normal University >> Beijing, China 100875 >> >